Often not a good idea.
But what if you can chew more than you think? What if you can start it all at once? If you went all in, could you finish it in three weeks, instead of three months?
Step by step is usually a smart choice, but a lot of times we see breakthroughs (foiling America’s Cup boats, the invention of twitter, and many more) happen with tight timeframes and an agreed-upon willingness to push the boundaries.